


Keeping scars

by Cadetwyrm



Series: Trans Trek AU [1]
Category: Star Trek: The Original Series
Genre: Alien Biology, Anal Fingering, Anal Sex, Bottom James T. Kirk, Knotting, M/M, Middle McCoy, Porn with some plot, Top Spock, Trans!McCoy, Vaginal Fingering, Vaginal Sex, Yeah Spock has a knot shut up, trans!Kirk
Language: English
Status: Completed
Published: 2020-05-14
Updated: 2020-05-14
Packaged: 2021-03-02 17:47:22
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,409
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24180814
Author URL: https://archiveofourown.org/users/Cadetwyrm/pseuds/Cadetwyrm
Summary: Spock learns some interesting things about his Captain and the Chief medical Officer, and even about his own culture. But he is always happy to learn new things.
Relationships: James T. Kirk/Leonard "Bones" McCoy/Spock
Series: Trans Trek AU [1]
Series URL: https://archiveofourown.org/series/1752751
Comments: 6
Kudos: 125





	Keeping scars

**Author's Note:**

> Look, this is half an excuse to write hot trans sex with my favorite three space boys(And live my vicarious Trans!Goals though Jim) and half an excuse to explore how Vulcans might handle Trans identities in their culture. I thought it sounded logical but I'm no Vulcan. Anyways, I hope you guys like it, I haven't written in years and this is my first time writing smut like this. So be gentle.

In the Dim lights of the captain's quarters, Spock is fascinated by the light scars under Jim's pecs, just a light ridge above the skin, almost invisible. But he can feel them under his sensitive finger tips, and through the contact he feels the man he is touching waiting for him to ask. He doesn't. Perhaps scars from a long won battle. But why not get them healed? The CMO was more than able too. Even the nurses could. The pride he feels though his touch tells him the answer.

It is when he removes Jim's regulation issue boxer briefs that the confusion starts.

Spock was not a doctor, had never studied human anatomy like their friend McCoy had, but he was familiar was some things. James T. Kirk was male. He, logically speaking, should have a (hopefully) erect penis and scrotum. And yet Spock was curiously looking over the visually pleasing folds of a labia, surely leading into a vaginal opening and eventually what Spock could assume was traditionally “female” biology. He could also see the clitoris clearly hard as it was, poked past the folds as a pseudo penis.

Jim, sensing the confusion and hesitation as his lover took his time looking over his lower anatomy, began to fidget.

“If you're not into vaginal,” He began, breaking the silence, “We can just do anal.”

He made the move to roll over but a strong vulcan hand shot out to grab his shoulder, stopping him. The measured power beneath it caused a hitch in the breath of his captain.

“I am not opposed to either Jim” He stated, as calm as always as he met those warm brown eyes with his own near black ones. “I am simply...” Confused. A human emotion,though Jim seemed to always bring such things about in him.

Ever perceptive, the man connected the dots. “Do... vulcans not have transgender individuals?” He propped himself up onto his elbows and the hand still on his shoulder didn't stop him, simply acting as a warm, heavy reminder that his first officer wasn't going anywhere.

“If so it is not something I am aware of.”While he knew much of his vulcan heritage and history it was impossible to know it all. “As I am sure you are aware vulcans keep such things private.”

“Logically.” A playful smile crossed the man's face as he used the vulcan's signature word against him. He takes a hold of the hand on his shoulder, removing it and tenderly squeezing it between both of his as he sits up fully. Spock can still feel uncertainty bubbling at the surface of his captain's mind, fear of rejection.

“Jim, I still have the full intention of having coitus with you.” Despite the quite sterile words, Jim's eyes go half lidded and the smile turns to a smirk.

“is that so?” His voice has gone husky and the lust from earlier that sparks like lit gunpowder from the very points of contact is back. “prove it, big boy.”

Spock opens his mouth to argue about the illogical nickname when tan arms surround him and he is pulled into the body below him.

***

“Spock?” The answer is curt, and through reading vulcan subtleties he can tell his father is confused by the call, and perhaps a little worried.

The half vulcan is perched at his desk in his quarters, sitting straight, elbows resting on the flat surface and fingers meeting at their points, eyes trained on his computer screen.

“Father.” He says in greeting. “How is Mother?”

“She is well, Spock. If that was your concern you should have called her.” Spock twitched his right eyebrow up slightly. His father must have been busy if he was being this impatient. He considered cutting the call short at that, and try again later, but his very human curiosity got the better of him. Curiosity killed the cat as the humans say.

'But satisfactions brings him back.' He recalls the doctor shooting back at the captain once, bouncing on the balls of his feet and smirking in the way he did when he thought he said something particularly clever, blue eyes sparkling. 

He mentally shakes the memory.

“That was not my intention of this call” He states, and his father waits for him to elaborate. “I have an inquiry about Vulcan culture.”

He sees his father's face shift, an eyebrow reaching towards his hairline and looking almost disbelieving.”You should be familiar with all our customs.”

Spock moved to fold his hands on his lap, sitting even straighter if possible. “I am not familiar with the topic of transgender identities concerning our people.” He admitted.

“It is a highly personal matter” Sarek begins but looks willing to educate his son on this topic.

Amanda once told Spock in private how much his father enjoyed teaching his son about his culture, that he was proud that his son embraced it so fully and completely. Spock at the time couldn't believe his father felt such an emotion for him. He still couldn't believe it but for new reasons more recently.

“It is logical that with the infinite possibilities that comes with creation, even in the procreation of sentient beings, that the mind and body and the perception of both do not always fall in line with each other.” Spock nodded. Logical indeed. “Individuals in which this effects work with their doctors to bridge the gap between mind and body. With a priest and only the closest friends and family they perform a ceremony, the name only privy to those who are part of it. They are 'reborn' and continue their life as their proper gender. Not even I am familiar with the custom in its entirety.”

Spock sat quietly for a few moments, taking the information in. It was fascinating that in all his formative years on Vulcan he had never met, or suspected to have met, any transgender individuals. It was only logical that vulcans were not as outspoken about this as humans were in their history. (He of course looked into it after his night with Jim) but if the statistic was as high as it was for humans it was almost impossible that he hadn't met any.

“Thank you father.”He said. “Please let mother know I will contact her soon.” A nod was all he needed before they shared a vulcan salute and a short recite of the vulcan parting sentiment before ending the call.

***

“Spock!” McCoy yelped as teeth sunk into the flesh of his neck. Not enough to leave a mark, which the good doctor could heal in an instant anyway, but enough for the curious response. He was leaning back against the hard, solid body of the vulcan first officer assaulting him. All consensual of course.

Deft hands moved below the blue medical scrubs across his taunt stomach and moving up. Spock could fell the confused lust coursing though him. The doctor has agreed to this, to join Jim and Spock in their sexual adventures as the captain had called them, but his affection for the vulcan was still a new and confusing development for him.

His body and emotions were telling, however. He was grinding back against the arousal in Spock's still immaculate uniform trousers, and along with the sparks of arousal, bursting forth as the hands traveled and the vulcan bit down again(another cry and a mark he would have to be healed before next shift) he could feel the warmth of romantic affection though their physical points of contact.

His hands continued roaming up, when they felt something familiar on the man's otherwise smooth skin under the bristle of his chest hair. Scars. He followed them with his fingers, tracing over the equal length just under his pecs. The rest of his movement stilled, his lips parting from the skin he had been worrying as a connection was made.

“Doctor.”

“Damn it, call me Leonard! We're in my damn quarters!” He bit out, still bumping back against the body behind him to draw more arousal out of him.

Spock ignores him. “You are Transgender.” It was a statement and a question in equal measure.

“So?” The hands that he had kept to himself until now moved to cup the vulcan's ass, squeezing in an attempt to get Spock to rock against him.

“You have a penis.” He pointed out, evident by the tent in the doctor's uniform trousers.

“Yeah and it would like some attention.” McCoy hissed. “Not everyone wants to keep their original equipment like Jim does.” He added as an afterthought.

“Fascinating.” The vulcan returned his lips to the doctor's neck, his hands moving up to nipples, and finding them not as sensitive as Jim's from the human's reaction, moved downward to his new goal.

McCoy gave a relieved sigh once the they reached their goal. He moved to help the science officer open the front of his uniform, pull down his underwear and grunted at the overly hot hand wrapping around his member.

“Can it produce sperm?” The vulcan asked curiously, with the same voice he would use to ask about any of the curiosities of humanity. He had scanned the history of medical transition in humans but not deeply so did not know the ins and outs of it.

“Viable even.” came the groaned response as the movement started.

“Fascinating.” 

McCoy gave a breathy laugh. “A medical miracle.” All other talking stopped as he was pushed towards his own bed.

***

The three of them finally had some free time together that wasn't spent collapsed together asleep in the captain's bed, exhausted from the latest mission. Spock had argued that he didn't need as much sleep as his human partners but didn't fight the arms curled around him either.

This was different though. It was shore leave and they finally had the chance to pleasure each other all at the same time instead of just pairs that took the briefest chances in their busy lives to feel the skin against skin of their lovers.

They were already naked, having taken the time to touch over each others bodies together, kissing, as an organized unit of eager limbs, lips and tounges. The humans haphazardly fell together on the bed, Jim moaning as the doctor's skilled fingers entered his folds. The vulcan was not far behind, gracefully crawling on top of them. While the hands had been exploratory before, it was like McCoy had flipped a switch in Jim, who quickly moved to grab Spock's alien biology, eagerly fingering at the duel ridges, gaining a pleasured sigh from him. The vulcan grabbed the lube from the bedside table and slicked a finger, pressing it into McCoy, both the men shivering together.

McCoy stretched Jim, Spock stretched McCoy and Jim used his hands to pleasure them both. For a while the cabin was full of human moans and breathy vulcan noises. But the captain could be inpatient. “If one of you don't fuck me soon I'm... I'm...” His threat was cut short moan as the doctor dipping down to take his clitoris(Or his T-dick as he affectionately sometimes calls it) into his mouth.

“'course, Darlin'” McCoy drawls out as he pulls back with a final lick. Spock, if he were human would have said reluctantly, pulls his fingers from his ass to allow the two the freedom of movement to prepare for penetration, sitting to the side.

“Doctor.” The vulcan gets disapproving looks from both humans, though brown eyes are more amused than the blue. “Leonard,” He corrects before continuing. “It would be illogical to continue without protection considering your respective biology.”

As if ignoring him, McCoy turns back to Jim and enters him, leaving the flustered man beneath him to explain once the initial moans die down. “No worries Spock” He said, meeting the vulcan's concerned gaze. “I got a.. a... fuck right there Bones.”

“Hysterectomy.” The doctor supplies in a grunt as he speeds up his pace.

The concern abated Spock nods and watches the two, how they knew each others bodies so well. He hoped one day to know their bodies as well, and their minds. He reached forward to gently touch them both, just enough to feel that spark of lust, that warmth of affection.

“C'mon Bones.”Jim moaned, watching Spock watch them. “Slow down a little. Can't you see our vulcan here wants a nice tight hole to slide into?” Spock noticed the flush on the doctor's cheeks grow, though he wasn't sure if it was from the statement or continued exertion.

“Fine.” McCoy slows down his pace, and Jim whines. “Plenty stretched, hobgoblin.” He assured, and Spock could feel the affection from the nickname.

He nodded and moved behind McCoy, space between the captain's legs becoming cramped as he straddled the doctor's legs. He took his cock in his hand, lining it up to the middle man's hole, sighing as his dark green head bumped against it a few times. Once McCoy slowed his pace to near stillness he slowly pressed in, earning a groan from both the men beneath him, the movement pushing McCoy deeper into Jim.

After a moment for everyone to adjust, he pulled out half way, and the eager doctor was quick to follow back, filling himself while emptying Jim, who didn't seem to appreciate this as he whined. But with a sharp push of Spock's hips both men were completely full again, causing pleasured cries. And just like that they made up a rhythm that suited them all. It was rough, but measured, Spock's hands causing bruises on McCoy's hips, before they moved to grab one each of his lovers' hands, wanting to feel their emotions equally. This caused the rhythm to change slightly, and by the surprised moan that came from McCoy he had hit his prostate. He looked over the shoulder in front of him and saw the pleasure, the affection for the men above him, that he could feel though where fingers touched his golden skin.

McCoy, perhaps deciding that the captain wasn't being pleasured quite enough, used his free hand to stroke Jim's pseudo penis, causing a jerk of delight that Spock could feel though the man he was balls deep in.

It took only a little over a minute, even Spock was too lost in the pleasure to calculate it down to the second, Jim was cumming, shaking below McCoy. “Bones!” He cried out, hand Spock's tightening, as with the one clutched in the sheets, toes curling.

“Fuck, Jim!” McCoy returned, and from the way his body stiffened, Spock knew he was following suit. He continued fucking them though their orgasms but slowed to a stop as his lovers went limp, holding the doctor up so he didn't crush their captain.

“Leonard, do you wish to continue?” He asked in a way that was meant to be even, but it was breathy and soft. He could easily meditate to lower his libido if they didn't.

McCoy growled as if the idea was blasphemous.”You better start fucking me you green blooded-” A surprised grunt interrupted him as Spock gave a sharp thrust, clearly pleased by the answer.

“Spock.” He and Jim met gazes, and he could see the mirth in his eyes. “Move Bones down so he can clean up his mess.”The motion to his dripping cream pie(The humans explained that euphemism to him at one point) cut the confusion before it began.

“I'm a Doctor not a damn janitor!” Said doctor exclaimed but didn't fight the vulcan as moved them, placing him so that his torso lay on the bed, hips bent and feet on the floor. McCoy looked up at Jim, grunting and groaning as the Vulcan started up again behind him. “Is that an order, Captain?”  
Without answering, Jim grabbed his hair and pulled him nose deep into his folds. By the noises Jim was making he took no time in starting.

When the captain was satisfied he let go of the tangles in his hand, and McCoy pulled back with deep intake of breath. They both looked very pleased and Spock could feel how much the rough behavior aroused him. And what he wouldn't give to taste that mouth, taste McCoy and Jim and their fluids all and once.

The thought rips out the first true moan out of him, causing a pleased chuckle from the man below him, and a grin a mile wide from Jim, which he only saw after he opened his eyes. When had they closed?

Jim seemed notice his loss in composure. “We're going to absolutely wreck you.” He said, eyes half closed and dark with his promise.

“Yeah we are.” McCoy agreed with a huff.

“Leonard, It appears that currently I am the one... 'wrecking' you.” Spock pointed out with another thrust, striking the prostate head on. If he were in a clear mind he would have admired how human technology could create and implant working prostates, but at the moment he was simply pleased to be causing the noises coming out of the gruff doctor. “Can you handle my knot this time?”

“Jesus, Spock!” Jim cried, and said man caught sight of him playing with his folds, fingers pressed around his clitoris.

McCoy's answer comes next. “Yeah, might as well try.” Last time they made love, Spock had not mentioned that part of anatomy and the sudden swelling caused the doctor to demand him to pull out in fear. Coming on his ass had been equally satisfying.

As he felt the heat building in the base of his cock, his closure coming, he realized that this was indeed love between the three of them. The thought warmed him to his core. He watched McCoy grab and claw at Jim's legs, short whines escaping him as the growing knot caught at his rim, the captain still playing with himself, fingers knuckle deep in himself. He was probably imagining the knot in himself, and another moan came from the vulcan at the thought.

'Claim' Came a thought deep within him. 'Mate.' It was an ancient hunger in him, getting stronger as he got closer. He ignored the instinct to bite McCoy's neck until he bled, but barely.

His knot was full, he couldn't move, in or out, and a wave of absolute pleasure rocked him. He groaned, eyes shut as he filled, and filled McCoy, his McCoy. His Leonard.

“Doesn't he cum absolute tons?” Jim purred, watching the two, very pleased.

“Yeah...” Came the breathy answer, barely a word, from the limp body of the doctor. 

“Vulcans...” Spock began, mind coming back to him as he opened his eyes. “Come from a very harsh climate. To ensure the viability of their mating, they produce copious amounts of seminal fluid. The knot ensures that rivals will not have time to remove said fluid before their mate can be fertilized.”

McCoy grunting, clearly coming back to himself, replied, “Don't need a biology lesson. Need a nap” Spock nodded and pulled his body to standing, careful to not pull at the knot, discovering a stain on the edge of the bed. He felt a bit of shame from the doctor as he realized his second orgasm was discovered.

“Do not worry, Leonard. I find it quite arousing you were able to achieve orgasm simply from our love making.” Spock assured and the shame eased.

“Damn hot.” Jim agreed as he scoots aside, allowing Spock to lay his two other lovers together on their sides. “And impressive for Spock. You gotta knot me next. Both holes.” He demanded.

Spock hummed in agreement, holding his Leonard, and looking forward to claiming his Jim in the same way.

Jim had stopped touching himself, folding his arms behind the back of his head as he watched the other two cuddle. After a few minutes he breaks the easy silence. “Spock?”

“Yes Jim?”

“Did you pull out every time and come on me because you thought I could get knocked up?”

Spock makes an almost silent snort at the euphemism. “Indeed.”

Jim chuckled and rolled on his side towards them, hands wondering over the arms around McCoy. Spock could feel the affection, for both of them, warmer and more present than lust. “I think this is going to work out just fine.” He stated. 

McCoy gave a sleepy huff of agreement, eyes shut and Spock nodded. “Indeed.”


End file.
